Mechanical stoker.



G. B. BAIT.

MECHANICAL STOKER. APPLICATION FILED JULY 29, 1910.

Patented Feb. 13, 1912.

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G. B. BAIT.

MECHANICAL STOKER. APPLICATION FILED JULY 29. 1910,

1,01'?,,1'70, Patented Feb. 13, 1912.

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G. B. RAIT.

MECHANICAL STOKER.

APPLICATION FILED JULY 29, 1910.

Patented Feb. 13, 1912.

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GEORGE B. BAIT, OF MINNEAPOLIS, MINNESOTE.

MECHANICAL STOKER.

Specification of Letters Patent.

Patented Feb. 13, 1912.

Application filed July 29, 1910. Serial No. 574,463.

To all'whom it may concern:

Be it known that I, GEORGE B. RArr, a citizen of the United States,residing at Minneapolis, in the county of Hennepin and State ofMinnesota, have invented a new and useful Improvement in MechanicalStokers, of which the following is a specification.

My invention relates to improvements in mechanical stokers and theapplication of mechanical stoking to railway locomotives.

My principal objects in this invention are. to improve the regularityand efficiency of the charging mechanism, to secure a betterdistribution of the fuel upon the fire grate and to improve the flexibleconductors connecting the engine and tender. These results are securedwithout complicating my device.

This application is an improvement upon the mechanism set forth in mycompanion application Serial Number 518,971, filed on September 22nd,1909, for improvement in locomotives.

In the drawings with which I have illustrated my invention and whichform part of my specification, Figure 1 is a plan view of my device inconnection with the framework of an engine and tender; Fig. 2 is asection on the line AA, Fig. 1; Fig. 3 is an enlarged detail of asection 011 the line B-B, Fig. 2; Fig. 4 is a sectional elevation of myflexible conveying tube showing its connection to the adjacent parts;Fig. 5 is a sectional View of the engine which I use in operating mydevice; Fig. 6 is a section on the line CC, Fig. 5, and Fig. 7 is apartial section on the lirfi D D, Fig. 1.

My device consists in general of a charging mechanism A which deliversfuel from the tender B to a flexible conveying tube G lying between thetender and engine, an expanded tube or coking chamber D which receivesthe fuel from the flexible conveyer, a grate E on which the fuel isdistributed, and the blowing mechanism F for distributing the fuel onthe grate. An engine G driven by steam from the locomotive boiler,operates the charging mechanism.

The chargingmechanism A, consists of an elongated hopper chamber 2 sunkin the platform of the tender and having a plunger 3 reciprocating in acylindrical groove 4 in its bottom. The hopper 2 has sloping lateralwalls 5 and a top or cover 6 flush-with the platform of the tender. Inthis cover 6 are a series of rectangular openings 7 permitting the fuelfrom the tender to drop through into the path of the reciprocatingplunger 3. These openings are sufiiciently large to receive coal of theordinary size and are separated by bridges 8 having reinforcing bars 9lying underneath them. The edges of the bridges 8 and of the reinforcingbars 9 beneath them, are formed with sharp corners adapting them tocrush the coal forced against them by the plunger 3. At its forwardend'lO, the hopper chamber 2 is reduced to a tubular form, connecting tothe flexible conveying tube. At its rearward end the wall of the chamberis formed with a lug 50 having an inclined upper surface 51. This lugacts as a guide for the rear portion of the plunger and fitting downclosely upon it prevents the fuel from working back behind the plunger.The forward end 11 of the plunger 3 is slightly hollowed, fitting it toengage the fuel in front of and above the plunger and carry it forwardduring its stroke. a

The upper portion of the plunger 3 lying above the groove 4 in thehopper chamber, is divided by depressions into a series of forwardlypointing teeth 12 which have abrupt front faces, sharp edges 13 andgraduallv sloping back faces 14.

The series of depression and forwardly pointing teeth 12 in the top ofthe plunger, form a convever adapted to gradually advance the fuelreceived at any point in the hopper chamber until it drops down in frontof the plunger and is forced forward through the flexible conveyingtubes C to the engine. The advancement of the fuel is accomplished bythe teeth of the plunger during its forward stroke by means of theirabrupt front faces engaging the particles and lumps of fuel and movingthem toward the front of the hopper chamber. As the plunger reverses itsmotion, the lumps of fuel thus moved forward encounter the resistance ofthe fuel lying above them and wedged against the bridges of the hopperchamber and remain substantially in the position they have reached,allowing the sloping faces 14: of the teeth 12 of the plunger to moveout from beneath them until its reverse stroke is completed, when a newforward movement of the fuel may take place by operating the plunger. Inthis way the fuel is moved forward step bystep from all parts 7 of thehopper chamber. When lumps of fuel too large to beaccommodated by thehopper chamber, drop into one of theopenings 7 in its cover, their loweredges are caught by the advancing teeth of the plunger and crushedbetween the sharp edges of the teeth and the sharp corners on thebridges 8 and their reinforcing bars. This crushing action will berepeated with each forward motion of the plunger until the refractorylumps are reduced to suitable dimensions. If the supply of fuel from oneof the openings 7 is temporarily checked by this crushing process, theother openings will aiforda more than sufiicient supply. In this way aconstant stream of uniform fuel is moved forward into the flexibleconveying tubes C. The reciprocating movement of the plungers is securedby the drive engine G operating through suitable mechanism which will bedescribed later in detail.

The form of the plunger may vary so long as it preserves the feature ofa series of forwardly projecting teeth having depressions between themtogether with abrupt faces and sloping backs. Thus a plunger ofrectangular cross-section, continuous lateral sides, and transverseteeth as described, would be within the meaning of this specification.

The tubes C afford a flexible cofiveying means between the tender andengine taking up slack motion and changes in elevation in the parts ofthe locomotive. My device de signed for this purpose consists of twotelescoping tubes 15 and 16 each joined to its respective part of thestoker, by. a spherical joint 17 allowing universal angular motion. Thespherical joint at the tender end of the tube C consists of a cup likeenlargement 18 of the tubular end of the hopper chamber into which fitsthe partly sphericalshell 19 at the end of the telescoping tube. Overthis part of the tube fits a mug 20 having a spherical inner face,and'bolts 21 joining it 'to the cup 18, by means of which a tight jointis made betweenthe cup and the sphericalend of the tube. The sphericalshape of these adjacent parts permits the movement of-the tube in alldirections through a considerable angle, and its backward end has abeveled edge 52' lying behindthe shoulder of the cup 181in'all positionsof the tube C thus preventing the forcingof particles of 7 fuel betweenthe-edges of the shell 19 and the cup 18. Betweenthe edge of the cup andthe flange of the ring, an oil cup '22 is formed admitting oil to thejoint between the two 'parts and thus lubricating 'the spherical joint.The spherical joint 17 at the engine endof the tube C is similar to thatat the tender end but the flanges of the cup" and ring forming theexterior of the joint, also form a split bearing 23 for the and therocker shaft 24 through which the plunge rs of the charging mechanismare operated.

By the comblned action of ,the two spherical joints and the telescopingjoint between the two parts of the tube, the tube C 1s accommodated toany possible motion between the tender and engine frames.

The forward end of the tube C opens into a tubular chamber continuouswith the coking chamber D. The chamber D lies below the level of thefire-grate E and slopes upward to the rear end of the grate, forming anunderfeed chamber in which the fuel is gradually brought to thetemperature of the fire grate, and in which the light gases of the fuelare driven off, allowing them to be I consumed by the incandescentmaterial lying above upon the fire grate E. As the; fuel is advanced bythe charging mechanism, it rises above the coking chamber in the form ofa mound from which it is distributed to I the grate by a mechanism Fwhich will be described in detail later.

The grate E used in connection with my improved device, is of theordinaryfinger bar type made up of a series of grate bars 25 lyingtransversely of the engine, having interlocking fingers supporting thefire, and fitted with a rock bar 26 by which they can be oscillated atpleasure through a small are.

The grate is .inclined forward and support.-

ed on the engine'frame in the usual manner.

A fire door 27 is provided ofthe usual type 1 and the entire locomotiveis adapted to hand stoking in case the mechanical stoker fails tooperate at any time. The distribution of the fuel over the grate isaccomplished by a blower F connected to the rim of the coking chamber Dand immediately above the level of the grate at that point. It consistsof a blowing ring 28' surrounding the opening of the coking chamber Dand having a number of twyer openings 29 directed upward and forward towhich blasts of steam and air are supplied for the purpose of blowingthe partially coked fuel forward upon the grate and to air in thecombustion of the mass of fuel in the chamber D. Partitions 3O dividethe blowing ring into, forward and rear segments 31 and '32respectively. The forward segment is supplied with exhaust steamthrough-the pipe 33. from the engine G which operates the chargingmechanism. In this segment of the ring, the twyer openings 29 aredirected partly upward [and partly forward fuel particles uniformly overthe surface of the grate.- The rear segment of the ring is suppliedwithlive steam direct from the boiler of thelocomotive passing througha pipeand air 'injectorI and thence to the ring. able form introducing amixture of live steam and air into the mass of partly coked blastthrough them distributes'the,

The air injector may be ofany suitcoal. The twyer openings 29 in thispart fire grate, to consume as far as possible the smoke gases arisingfromthe coking process and to drive these gases forward through theincandescent fuel upon the fire grate for their further combustion, thusproducing complete and uniform consumption of the fuel, with the mostintense heat near the boiler and a minimum of resultant smoke.

The engine G which operates the reciprocating plungers 3 of the chargingmechanism A and supplies exhaust steam to the blowing rings 28, consistsof a differential piston 34 working in a horizontal cylinder 35 attachedto the chamber D and has a three-way valve 36 operated by a valve" rod37 and a hand lever 38 situated near the firemans seat, by means ofwhich the charging mechanism A can be operated at pleasure by thefireman. The three-way valve 36 has a live steam port 53, an' exhaustport 54 and a by-pass 55. A grease cup 56 and passages 57 provide forthe lubrication of the valve. A connecting rod 39 is pivoted upon thepiston and connects with the crank 40 and rockshaft 24 on which a bellcrank 41 is mounted. To the head of this bell crank is pivoted aconnecting rod 42 having a swivel joint 43 and attached to a drive yoke44 by a universal joint 45. This combination of pivot and threadedjoint-s allows complete flexibility between the engine and tenderframes, without interfering with the operation of the drive yoke. Thedrive yoke 44 is illustrated in connection with two stoking units lyingside by side and delivering fuel to the two lateral sides of the firegrate. The drive yoke is formed with a body 46 and two arms 47 eachattached to a plunger by a tenon mortised into the side of the plungerand fastened by two stud bolts 48. The arms slide in guide slots 49 inthe side of the hopper chamber.

When the fire-man of the locomotive. has supplied fuel for the chargingmechanism, he turns the hand lever 38 supplying steam to the engine Gand causing the forward movement of the plunger 3. Reversing the handlever retracts the plunger and this process is kept up as long andfrequently as the coal supply on the grate requires.

In accordance with the patent statutes I have described the principlesof operation of my invention together with the apparatus.

which I now consider to represent the best embodiment thereof but Idesire to have it understood that the construction shown is onlyillustrative and that the invention can be carried out by other meansand applied to uses other than those above set forth within the scope ofthe following claims.

Having described my invention, what I claim as new and desire to protectby Let-v ters Patent is 1. In a mechanical stoking device, areciprocating plunger, a series of forwardly pointing transverse teethon said plunger adapted to engage and move forward fuel lodged on saidteeth, a transverse bar above said teeth having a sharp rearward corneradapted to cooperate with said teeth, and means for operating saidplunger, whereby lumps of fuel fed to the stoker are adapted to becrushed between said teeth and bar and to be advanced by the succeedingteeth of said plunger. D

2. In a mechanical stoker, an elongated hopper chamber having a groovedbottom and bridges across its top dividing the top into a series ofopenings having sharp corners, a plunger reciprocating in said groove, aplurality of forwardly pointing teeth on said plunger adapted tocooperate with the sharp corners of said bridges in breaking up lumps ofcoal caught between them, and means for actuating said plunger.

3. A mechanical stoker for locomotives, comprising, in combination, atender, a fire grate for said locomotive, a charging mechanism on thetender, an underfeed coking chamber below the firegrate of saidlocomotive, and a flexible tubular connection from said chargingmechanism to said coking chamber, the charging mechanism being formedwith a reciprocating plunger adapted to advance "fuel from the tenderthrough said flexible connection and coking chamber to said grate, atwyerelement lying at the rear of the opening of said coking chamber onthe grate and having openings directed forward across said chamberopening, a second twyer element lying at the front of said chamberopening and having blast openings directed upward and forward across thegrate, and means for supplying live steam and air to said rear twyer andexhaust steam to said front twyer, whereby the draft and the combustionof gases in said coking chamber may be promoted and the fuel ad vancedalong the grate.

4. In a mechanical stoker for locomotives, an underfeed coking chamberopening into said locomotive, a force feed of fuel connected thereto, asegmental twyer ring in connection with said coking chamber, having asegment lying to the rear of the opening of said coking chamber andadapted to pass a constituent into the fuel coking therein to promotecombustion, and a second segment lying in front of the opening of saidcoking chamber and adapted to supply a distributing blast for thedistribution of the coked fuel within said locomotive.

5. In a mechanical stoker for 1ocomotives,'

an engine, a fuel distributer thereon, a tender, an elongated hopperchamber thereon, having a grooved bottom, a bridge across said chamberhaving a sharp corner; a plunger reciprocating in said groove, aplurality of forwardly pointing teeth on said plunger a aptedtocooperate with said sharp corner on said bridge in breaking lumps offuel, a tube connecting said hopper chamber and said fuel distributer, auniversal joint interposedin said tube between its ends; and means foroperating said plunger and said distributer.

In testimony whereof, I have signed my 15- name to this specification,in the presence of GUSTAVUS LOEVINGER, F. G. BRADBUnY.

